PROJECT SUMMARY/ABSTRACT There continues to be a major gap between the global burden of mental illness and the number of patients receiving adequate treatment. To address this gap in low- and middle-income countries, a key strategy has been the use of primary care health workers to detect and deliver of care for mental illness. The World Health Organization has developed the mental health Gap Action Programme (mhGAP) to train primary care workers to detect mental illness and deliver evidence-supported treatment. However, research to date suggests that implementation strategies for mhGAP are inadequate as evidenced by low detection rates, with multiple studies demonstrating post-training detection at fewer than 10% of persons with mental illness detected. A potential barrier to effective implementation of detection in primary care is stigma among primary care workers against persons with mental illness. Our preliminary work suggests that reducing primary care workers' stigma against persons with mental illness may improve accurate detection of mental illness. We developed a version of mhGAP training that includes a stigma reduction component: ?REducing Stigma among HealthcAre ProvidErs? (RESHAPE). In RESHAPE, persons with mental illness (i.e., mental health service users) are trained to share recovery stories, conduct myth-busting sessions, and promote mental health advocacy. Our preliminary studies of RESHAPE suggest that involvement of mental health service users in training primary care workers reduces stigma, and that stigma reduction may mediate improved detection of mental illness. We are proposing a hybrid implementation-effectiveness (Type-3) cluster randomized controlled trial in Nepal comparing mhGAP standard implementation with the RESHAPE implementation strategy. Target conditions will be depression, generalized anxiety, psychotic disorders, and alcohol use disorder. In Aim 1, we will evaluate the impact of the RESHAPE service user engagement on stigma among primary care workers. In Aim 2, we will evaluate the impact of the RESHAPE training on accurate reach of services (i.e., detection) and evaluate stigma as a mediator of differences in accuracy. Building on the same theoretical approaches to stigma in our primary research study, for Aim 3 we will conduct capacity building activities with to promote greater involvement of service users in research. We will also address conduct activities to counter gender- related stigma in mental health research careers. Successful completion of these aims will contribute to the NIMH Strategic Plan employing implementation science to maximize the public health impact of research and involve service users. This research advances the Fogarty International Center's mission for implementation science and commitment to evidence-based stigma reduction. We will build capacity by reducing institutional barriers to gender equity in research. These findings will shed light on the potential role of service users to improve implementation and accuracy of mental illness screening programs in primary care settings.